Type II Non-Insulin-Dependent Diabetes Mellitus affects 3% of Americans and is responsible for a great deal of human morbidity and mortality. Treatment of diabetes and its complication accounts for 1 in 7 dollars spent for health care in the U.S. Diabetes is also a highly inherited disease. However, the genes that are responsible for diabetes and which cause it to run in families are unknown. Recently, technology has been developed which makes it feasible to identify genes causing diabetes, and that is the goal of this research project. Families with multiple diabetic members will be identified, and family members will be studied from a clinical and metabolic perspective. Blood will be obtained so that genes or DNA can be extracted from blood cells. Regions of DNA will the be assessed which are associated with the presence of diabetes in individual family members, and this will indicate that the abnormal gene causing diabetes is located in this region. We will initially concentrate efforts on African-American families with diabetes since diabetes is more common in this racial group making it easier to find the abnormal genes. Once the genes are known, it will be possible to develop effective treatment for diabetes, and this could even suggest ways to prevent or cure the disease.